Volcanoes and carbon dioxide emissions

Walter Williams states in his March 5 column that "just three volcanic eruptions-Indonesia (1883), Alaska (1912) and Iceland (1947)- have spewed more carbon dioxide into the atmosphere than all of mankind's activities during our entire history."

Dr. Williams presumably bases this conclusion on the book "Heaven and Earth" by the Australian geologist I. Pliner. However, it appears that Pliner's study has been thoroughly discredited, and the fact-checking website Snopes says this about the subject: "The myth that a single volcanic eruption puts more CO2 into the atmosphere than all of mankind to date, let alone 10,000 times more, is one of the most pervasive as well as one of the most demonstrably false climatological claims out there."

Snopes goes on to cite several sources to support this statement. One such is a paper by T. Gerlach published in the Transactions of the American Geophysical Union in 2011 titled "Volcanic versus Anthropogenic Carbon Dioxide" which explains that the carbon dioxide emission rate on an annual basis by man-made activities is well over 100 times that of volcanic emissions.

It seems that Dr. Williams, in his zeal to promote the idea of an indestructible planet, has relied on a statistic that is, at best, of dubious accuracy.

Dick Page

Naperville